Various industries have found that central packaging for distant markets is a beneficial approach in their business activity and can assist them in developing strong market bases. There is an increased emphasis on volume producing and marketing. Product markets may extend across international boundaries. Thus, out of both necessity and convenience, situations have developed where individual producers may service vast market areas. Hence, longer shelf life, particularly for difficult-to-contain liquids, is needed so that producers and suppliers can provide uniform top quality merchandise throughout expanded areas of distribution.
It is well known that the incorporation of a layer of aluminum foil generally serves as a means of preventing oxygen and ultra violet light rays from penetrating through the walls of a paperboard container. However, when longer than normal shelf life is desired, additional precautions must be taken to assure better resistance to edge wicking resulting in wall bulge and/or liquid staining through the wall of the paperboard container.
Heretofore, internal raw edges have been eliminated in various ways. The edge portions of internal side seam panels have been folded double with the raw edge half confined adjacent the outer wall panel, as disclosed in Miller et al U.S. Pat. No. 3,294,310. Other known techniques have included "skiving" or cutting away a portion of the thickness of the side seam panel edge portion so that, when folded onto the adjacent unskived wall, the overall thickness thereof is less than double thickness, as disclosed in Braun U.S. Pat. No. 3,604,317. Schwenk U.S. Pat. No. 3,654,842 illustrates a method of skiving wherein the skived portion only is folded double to thereby eliminate the raw edge while maintaining a single wall thickness.
Still other techniques have included various applicator mechanisms and methods whereby the raw edges of sheet material, before being cut into individual blanks, are covered with a suitable thermoplastic sealing material, as shown and described in Battersby et al U.S. Pat. No. 3,213,890, Stamp et al U.S. Pat. No. 3,664,296, and Replogle U.S. Pat. No. 1,316,805.
In addition to the above, McNair, Jr. et al U.S. Pat. No. 3,365,111 illustrates in FIGS. 8A and 8B thereof a container wall panel having an edge portion skived on an angle, but with layers of polyethylene, aluminum foil and polyethylene extending beyond the angled edge and folded onto the adjacent wall panel so as to be sealed thereto.